Method of and apparatus for treating metal surfaces



Rf H. GORDON Aug. 10, 193 7.

METHOD OF AND APPARATUS FOR TREATING METAL SURFACES Filed Mayb', 1935 5Sheets-Sheet l I N VEN TOR.

A TTORNEY6 Aug. l0, 1937.' R. H. GORDON METHOD OF AND APPARATUS FORTREATING METAL SURFACES- Filed Hay 3, 1935 5 sheets-sheet l N Vf ."JTOR.

I ATTORNEYS,

Aug. l0, 1937.

R. H. G oRDoN METHOD OF AND APPARATUS FOR TREATING METAL SURFACES FiledHay 3, 1935 5 'Sheets-Sheet 3 INVENTOR. aer /1 Gordo,

ATTORNEYS.

11|. IIIII l Aug. 1o, 1937.

METHOD OF AND APPARATUS FOR TREATING METAL SURFACES R. H. GORDON FiledMay 3, 1935 5 Sheets-Sheet 4 INVENTOR.

ATTORNEYS.

ug. 1G, i937. n R M GQRDON 2,089,648

METHOD OF AND APPARATUS FOR TREATING METAL SURFACES I Filed lay 5, 19355 Shqets-Sheet 5 NVENTOR. oeri /vf @arden ATTORNEYS.

Patented Aug. 10, 1937- UNiTED STATES Vw-uENT oEElcE METHOD oF ANDAPPARATUS Fon TREAT- mG METAL simmons Robert H. Gordon, Detroit, Mich.,assigner to Parker Rust Proof Company, a. corporation of MichiganApplication May 3, 1935, Serial No. 19,556

12 Claims.

the character which react with the metalof the4 articles to form aprotective coating thereon.

The reaction which takes place between the metal under treatment and thesolution used in a rustproong process of this character is accompaniedby the formation of a occulent precipitation and/or scale whichfrequently so fouls the solution as to render it unsuitablelfor repeatedre-use, particularly in a spraying system 'having nozzles provided withrelatively small outlet orifices.

One of the main objects of the invention is to provide for the removalof contaminating solid matter from the rustproong solution and from thecontainer and conduits thereof so that the solution can be repeatedlyre-used and discharged.

from spray nozzles having relatively small outle orifices withoutclogging the latter.

Other objects of the invention are to provide improved means forallowing the solid matter of the used rustprooilng solution to settleout of suspension before returning to the discharge spray nozzles; toprovide a rustproofing solution tank having a sump therein forcollecting the main portion of the solid constituents of the usedsolution; to provide means for causing the solution to travel through atortuous course in returning to the discharge nozzle so as to prolongthe period during which settling of the solid particles may take place;and to provide means of this character which so directs the flow ofsolution during the settling stage as to prevent the transfer ofdeposited solid matter from' the 40 region of the sump to the'conduitsby which the nozzles are supplied with solution. y

A'further object of the invention is to provide controllable,interconnected rustproof. spraying Y and rinsing units by which both therustproofing solution and the rinsing liquid can be rel used andre-circulated repeatedly.

Additional objects of the invention are to provide a supply tank'in therinsing unit which may be used to accommodate the rustprooiing solutionduring flushing and cleaning of the rust-V proong unit; to provide asystem of conduits for conveying 'the solution from its Vnormaltank tothe spray nozzles, which is so connected with the tank of the rinsingunit as-to facilitate the transfer of the solution thereto beforeflushing the rustproong unit tank, and to return the solution directlytothe spray nozzle of the rustprooflng unit after the cleaning andushing operation has been completed; to provide a single pump forpropelling the solution 'through the rustproong unit, transferring thesolution to' the rinse liquid tank as well as for circulating theilushing liquid throughout all portions of the rustprooiing unit'andreturning the solution to the nozzle throughwhichfit is lnormallydischarged during operation; to provide valve means in a system ofcbnduits of this character for selectively conditioning the latter toaccomplish any of the foregoing results; and to provide means for ushlngall portions of the rustproong unit through which the solutiontravelsduring normal operation of the system'.

Still further objects oithe invention. are to y provide closed,re-circulating rustproong solution and rinse liquid systems whichrequire the provision of only a relatively small quantity of solution'orrinse liquid at any one time; to provide closed spraying systems of thischaracter, the contents of which are not subjected to loss byevaporation; .to provide provedmeans for replenishing the rust proo gcirculating system with a solute in order to increase or maintainconstant the concentration of the solution; and to provide automaticmeans for maintaining the rustprooilng solution at a substantiallyconstant elevation in its supply tank.v f

'I'he above being among the objects of the present invention, the sameconsists in certain novel features o1' commotion and combinationsofparts to be hereinafter described with reference to the accompanyingdrawings land then claimed, having the above and other objects in view.l

An illustrative embodiment of the invention is Vshown inthe accompanyingdrawings, in which:

Fig. 1 is a longitudinal, side elevational view oi a rustprooflngapparatlm embodying the inadjacent the rustproong unit thereof and whichextends between the extremities of the line'3-3 of Fig. 1;

Fig. 4 is a top planview of the acid rinsing section of theapparatuswhich is disposedA at the end thereof opposite therustprooilngunit and Fig. 6 is anl emargeaside. elevational view of the rstrinsingsectionjbf the apparatus Fig. '7 is an enlarged side elevationalview of the second, or acid rinsing station of the apiparatus.

.In the form of the invention illustrated in' the drawings, therustproong apparatus includes a plurality of aligned, adjacent units,generally designated in Fig. 1 by the numerals l0, II and I2, eachcomprisinga substantially rectangulai` sheet metal casing I3, I4-or I5,respectively, having registering opened "extremities for accommodatingthe passage through the apparatus of articles to be treated. Thearticles may be supported by, and propelled through the apparatus by aconveyor, generally designated by the numeral I6, or other suitablemeans. 'I'heunit I0 of the apparatus through which the articles areinitially passed, is provided with a rustproofng solution sprayingsystem for applying to the articles a rustproofing solution of thecharacter which reacts with the metal thereof to form an exteriorprotective coating' thereon. The

second unitl II y'through which'the articles pass, contains a rinseliquid spraying system which preferably discharges water, or any othersuitable liquid, on the treated surfaces of the article so as to removesubstantially all the rustprooing solution adhering thereto.' The unitI2 of the apparatus is provided with an acid rinse spraying system forfinally treating the articles and their rust resisting coatingspreparatory to delivery from the apparatus.

The rustproofihg'nit I0 includes a spraying chamber I'I-jinadvance ofwhich is provided a pre-heating chamber I8 having a heating coil I9disposed adjacent each vertical side wall thereof. The 'heating coils I9are supplied with steam from a suitable source (not shown) by a pipeline 20. Although heating of the articles before entering the sprayingchamber I8 is not essential, by increasing the ten'iperature thereof thechemical reaction 'of the rustproong 'solution upon the articles isstimulated and. thetir'ne required for treatment thereof in .thesplfaychamber I'I is reduced.

Extending longitudinally of the sprayingchamber I 1, adjacent the roofv2,I,. and the vertical side walls thereof are header pipes 22and 23respectively. The header pipes 22 and 2.3 are provided 'withlongitudinally spaced, downwardly extending branch pipes 24 which aredisposed adjacent the opposite side walls of the spraying-chamber andprovided with inwardly extending nozzles 25. Disposed between theheaderpipes 22 and 23 are longitudinally disposed and laterally spacedbranch pipes 26 which vextend longitudinally of the drying chamber'at alocation slightly above the header pipes andv which are provided withoutlet nozzlesl 2l 'thatare directed downwardly 4toward thecentralportion orf-the spraying chamber."' The right -end portions of theheader pipes 22 and'23 and the branch pipe 26 communicate wi-th'afsupplyconduit 28 which extends transversely of the rustprooi'ing apparatus, asillustrated in Fig. 3.? The flow of rustproofing solution fromthe-supply conduit 28 to the foregoing header pipes-and branch pipes maybe selectively controlled by a valve 29" with which each pipe isprovided. The branch pipes of the rustproof solution spraying system maybe disposed in any suitable relationship with respect to each other andwith respect tothe spraying chamber and the nozzles thereof may bearranged to spray the solution in any desired direction as required bythe particular shape and contour of. the articles operated upon.

The supply-conduit 28 communicates with the outlet of a pump 29 which isldriven by an electric motor 30, or other suitable means. 'Ihe inlet ofthe pump 29 is connected by a conduit 3I, having a control {ialve 32therein, with a removable stand pipe 33 disposed in a tank 34 that islocated directly below the spraying chamber I'I. The tank 34 has aleftwardly declined top wall 35, as viewed in Fig. 5, which extends fromthe right end portion of the tank to within limited spaced relationshipof the left end wall thereof. 'I'he space between the left extremity ofthe inclined top wall l35 andthe left end wall of the tank provides aninlet opening 35' through which excess rustproong solution discharged bythe spraying system may enter the interior of the tank. Provided at theleft -end portion' of the tank 34 is a downwardly extending sump 36, aportion of which registers vertically with the inlet opening 35.

'I'he sump 36 and the portions of the tank 3d immediately thereabove areinternally divided by a partition 31 which extends from the uppermostvertical side wall of the tank, as viewed in Fig. 2, to Within spacedrelationship of the opposite side wall of the tank. 'I'his partitionextends transversely of the tank 34 and sump 35 and permits the ilow ofrustproofing solution only around the vertical extremity 38 of thepartition. Spaced longitudinally of the remaining portion of the lengthof the tank 34 are vertically extending',

partitions 39. successively -adjacent partitions 39 extend inwardlytransversely from the opposite vertical side walls of the tankrespectively. Each partition 39 is substantially narrower than the widthof the tank and the inner extremitiesv of; the sump 36 to the stand pipe33 and outlet pipe 3l with'which the latter is connected.

The provision of the tortuous path for the used rustprooflng solutionprolongs the time of travel thereof from the inlet of the tank to the`outlet and thus provides ample time for suspended particles of solidmatter' to settle out of the solution. The main portion of the solidconstituents of the used rustproong solution is deposited in the sump36, but any solid matter which is carried past the'latter settles on the.lower floor portion 40 of the tank 34. The deposited sludge may beremoved periodically through openings provided in the top wall of thetank located externally of thespraying chamber. These openings arenormally closed by hinged covers 4I. The stand pipe/33 is provided withstaggered longitudinally extending slots 42 having lower'extremitieslocated sufficiently above .the floor 4o of the tank to insure theseparation -of the clean solution from the deposited solid matter duringpassage of the solution into theY stand pipe. Filters 39' may beprovided between theinner extremities o f the partitions 39 and theassociated vertical side walls of the tank to assist in removal ofsuspended particles of solid matter from the solution.

The rst rinsingunit Il shown in plan and side. elevational views inFigs. 3 and 6, respectively, is provided with a spraying chamber 43having upper longitudinally extending header pipes 44 and 4 5, eachlocated adjacent the upper wall of the spraying chamber 43 and in closeproximity to one of the respectively opposite side walls thereof. Theheader pipes 44 and 45 are provided with downwardly extending branchpipes 46, each of which has a plurality of vertically spaced nozzles A41directed inwardly for spraying rinse liquid toward the central portionof the spraying chamber. These header pipes communicate with a. supplyconduit 48 which leads to the outlet of a pump 49 that is driven by anelectric motor 50, or any suitable driving means. Rinse liquid conveyingpipes 5l extend longitudinally of the spraying chamber 43 insubstantially parallel relationship to the header pipes 44 and 45 andthey communicate with" the rinse liquid supply conduit 48, asillustrated in Fig. 3. The pipes 5l are provided with downwardlydirected nozzles 52, spaced longitudinally thereof, which dischargerinsing liquid downwardly toward the lower portion of the spray chamber.The various pipes and branch passages of this spraying system may bearranged in any desired manner to so direct the rinse liquid sprays asto subject all portions of the articles operated upon to a thoroughrinsing operation.

Disposed below the rinse liquid spraying chamber 43 is a collecting tank53 which extends laterally from one side Wall of the rinse liquidspraying chamber 43, as illustrated in Fig. 3. The tank 53 has an openupper extremity for accommodatingthe reception of the spray liquiddischarged from the nozzles-41 and 52. Provided at the left end of thetank 53, as viewed in Fig. 6,

,is an outlet 54 which is connected by a conduit 55 with the inlets ofthe rinse liquid supply pump 49. The conduit 55 is provided with a valve56 for controlling the iiow of rinse liquid to the inlet of the pump andby which the ow may be completely cut oi. The tank 53 has a secondoutlet 51 at its lower left hand extremity, as viewed in Fig. 6, whichis communicatively connected by a pipe 58, having a valve 59 therein,with the inlet of the rustprooiing solution pump 29. Leading from theupper left hand extremity of the tank 53 isgan inlet pipe 60 whichcommunicates with'the rustproofing solution supply conduit 28 and whichis provided with a control -proong apparatus, but when it becomesnecessary to flush the rustproonng system, the rinse liquid tank 53 maybe drained through an outlet 63 having a control valve 64, so as toprovide space for accommodating the rustproong solution which may 'betransferred thereto from the rustproonng unit l0 by the action of thepump 29.

is forced by the pressure of the pump 29 through the lower section ofthe conduit 28, pipe 60 and into the tank 53, whereas the flow ofrustproofing solution from the tank 53 is prevented by the valve 59.

After the rustproong solution has been transferred to the tank 53, thevalve 6I is closed and the valve 59 remains closed so as to entrap therustproong solution in the tank 53. Water or any other flushing liquidis then introduced into the tank 34 and sump 35 of the rustprooilrigunit I0 through a branch pipe 56 which communicates with a liquid supplyline 61, as illustrated in Fig. 5. The flow of the flushing liquidthrough the branch pipe 66is controlled by a manually operable valve61'. This branch pipe 66 is also employed to supply water or otherliquid to the tank 34 during normal operation of the apparatus, througha by-pass pipe 68 connected with the branch pipe 66 above the valve 61and provided with an automatically operable valve 69. The valve 69 isautomatically actuated to maintain a predetermined level of liquid inthe tank 34 by a rod 10 which is pivotally connected with a lever arm1I. The lever 1l is pivotally mounted on an axis 12 and located withinthe tank. The right end of the lever 1| is provided with a oat ball 13and the left end thereof is provided with an adjustable Weight 14. 'Iheweight 14 and the oat ball 13 are normally in balanced relationship withrespect to the axis 12, so that as the liquid in the tank 34 raises thefloat ball 13, the lever 1I is turned in a counter-clockwise directionand the rod 19 is moved downwardly to close v the valve 69and'maintainthe latter closed until 3- 29. l'Ihe pump 29 then circulatesthe liquid through the supply conduit 28 and the associated sprayingsystem of the rustproonng unit I0 as long as is required to thoroughlyflush the same. Then operation of the pump 29 is discontinued and theflushing liquid is removed from the tank 34 through a drain 15 having acontrol valve 15 and located at the lower left hand extremity of thesump 36. The rustproong solution temporarily stored in the tank 53 ofthe rinsing unit il may then be returned to the rustproong unit I9through the spray nozzles 25 and 21 thereof by opening the valve 59 andclosing the valve 32 in the outlet pipe 3l of the rustproong solutiontank 34 so as to allow the rustproofing solution to now through the pipe58 into the inlet of the pump 29 and from the latter through the supplyconduit 28 to the spraying system. ter the tank 53 has been emptied ofrustprooiing solution, the valve 59 is again closed and the normaloutlet valve 56 of the tank 53 and outlet valve 32 of the tank 34 areopened.' A new charge of rinsing liquid is introduced into the tank 53through the branch pipe 11 which communicates with the liquid supplypipe 61 and through which the now of liquid is controlled by a valve 18.When the tank 53 has again been re-charged with rinsing liquid, themotor 50 may bestarted to drive the pump 49 so as to circulate therinsing liquid from the tank 53 through the supply con'- duit 48 andnozzles'41 and 520i the rinse liquid ber I8 of the rustprooflng unit |0.The mixing drum 1.9 has an upper wall 80 on which is mounted an electricmotor 8|, or other suitable driving means, having a shaft 82 extendingcentrally of the drum and provided at its inner end with a mixer, orpaddle 83 by which the materials used to replenish the solute of therustproong solution may be thoroughly mixed and incorporated together.The mixing drum 19 is provided with an outlet conduit 84 which isadapted to discharge any desired quantity of the contents of the drum 19into a funnel 86 provided with an outlet 31 which communicates with theinterior of the rustproong'solution tank 34, as shown in Fig. 5. Theoutlet conduit 84 has a valve 85 by which the flow of the contents ofthe drumy 19 to the tank 34 may be manually controlled.

'I'he acid rinsing unit l2 also includes a spraying chamber 89' havingan independent closed, Spraying system comprising a pair of header pipes88 and 89, each locatedl at the upper extremity of the chamber 89 anddisposed adjacent one of the vertical side walls thereof respectively.The

vheader pipes 88 and 89 are provided with longilower left handextremity, as viewed in Fig. 7,.

tudinally spaced downwardly extending branch Pipes 90 vwhich are locatedadjacent the respectively opposite vertical side walls of the acid rinsespraying chamber and which have verticalf 1y spaced, inwardly directednozzles 9| for dis'- charging the acid rinse liquid inwardly toward thecentral portions of the spray chamber. The header pipes 88 and 89communicate with an acid rinse liquid supply conduit 92 which lead fromthe outlet of a pump 93 that is drivingly connected with an electricmotor 94, or other suitable driving means. Pipes 95 which communicatewith vthe header 92 and extend longitudinally of the acid rinse liquidspraying chamber are disposed adjacent the upper wall of the latter andprovided with downwardly directed spray ,nozzles 96. The nozzles of thevarious branches `of the acid rinse spraying system may be directed inany desired manner as required by the particularshape and contour of thearticles operated upon inv order to subject substantially all portionsof suchartir cles to action of the spray nozzles.

An acid rinse collecting tank 91 having an upper open. extremity isdisposedbelow the acid rinse spraying chamber 80 and provided at itsVwith an outlet pipe 98 that communicates with the inlet of the pump 93.A lter '99 extending transversely of the tank 91 may be provided at theleft end portion thereof for preventing the ow of any solid matter,which may be v,removed from the articles operated upon and introducedinto the acid rinsing liquid, from owing throughthe outlet 98 and pump93 so as to prevent particles of solid material from beingl delivered tothe nozzles and clogging the latter. Access may be had to the interiorof the acid rinse spraying chamberthl'ough av doorway |00 provided inonevertical ansehen side wall thereof. The header pipes v88 and 89 andthe pipes 95 are provided with individual control valves |0| by whichthe iiow of acid rinsing liquidl to the various nozzles thereof may beindividually controlled. Leading from the low ermost left hand portionof the tank 91 is a drain outlet |02 having a valve |03, through whichthe acid rinse liquid may be removed from the tank 91. The solvent ofthe acid rinse liquid, which is preferably water, may be introduced intothe tank 91 through abranch pipe |04 which communicates with the pipe 61that is common to all three of the units of the apparatus. The interiorof the tank 91 may be cleaned through openings in a laterally4protruding portion therei of which are normally closed by hinged'covers- |05. Any one of the doors |05 may be opened to permit pouringof a suitable acid into the tank 19 during re-charging thereof and afterthe tank has been filled to a desired extent with water.

In Fig. 5 is illustrated an improved method for heating the rustprooiingsolution while the latter is contained in the rustproofing solution tank34. Thissame construction may be used in heat-l ing either the rinseliquid of the first rinsing unit or the acid rinsing liquid of thesecond rinsing unit. Adjacent ne or bothsides of the partition 39 may belocated'v a 'vertically disposed heating coil |06 which is preferablysupplied with steam through the steam li'e 20 and associated branchesthereof. The heating coils |96 are preferably located sufpiently abovethe bottom of the tank 34 and 'preferably so spaced from the sump 36 asto Aprevent churning of the rustproofing solution and re-mixing of the`depositedsolid matter therein. Each heatingcoil |96 is provided with anindividual controhvalve |01 by which 'articles operated upon through aspraying system without clogging the outlet orices of the spray theapplication of steam thereto may be regug nozzles thereof and withoutrequiring frequent shut down and cleaning. When it becomes necessarytothoroughly clean the system, this may be accomplished withoutwastingthe rustprcong Q solution and without the requirement of a largetankfor-temporarily storing the solution.- This is accomplished by utilizingthe tank Vof the rinse liquid spray system for this purpose. During theilushing operation all of the passages .whichiare apt to become cloggedor contaminated in any way by reason of the reaction of the rustproongsolution therewith, are thoroughlycleaned and subjected to the actionofthe ushing liquid for the latter is circulated through each and everyconduit, nozzle, branch passage, receptacle and f pump through which therustproong solution is normally passed. The rustproong solution tank andassociated sump are so constructed and provided with means lfor causingthe solution to travel through atortuous path that substantially noneofthe occulent precipitate or scale formed during the reaction of therustproong solutionqupon the articles under treatment is allowed tore-enter the pump during re-circulation of the solution.

All parts ofthe system-,with which the rustproofing solution contactsare preferably formed of'metal which is not subject to reaction there,-

with. The walls of the spraying chamber I1 and the tank 34 preferablycomprise Monel metal but they may be formed of Wood suitably treated toprevent leakage of the solution therethrough. The pipes cf the spraysystem through which the rustproong solution passes may also be formedof suitable metal which is not reacted upon by the solution.

Although but one specific embodiment has been described and illustrated,it will be apparent to those skilled in the art that formal changes mayI be made in the invention Without departing from the spiritandsubstance of the broad invention, the scope of which is commensuratewith the appended claims.

What I claim is: l

l. The method of rustproong metal articles which consists in sprayingthereon a rustprooing solution of the character which reacts chemicallywith the metal of said articles to form a protective coating, collectingthe excess sprayed solution within a tank, causing said collectedsolution to flow through a tortuous path Within said tank from thelocation at which it is collected therein to alocation from which it maybe removed from and re-sprayed on articles to be treated so as toprovide time for substantially all solid matter to settle out ofsuspension in said solution and respraying the resulting collectedsolution on articles to be treated.

2. In a rustproong apparatus having means for continuously spraying and`respraying a rustproong solution of the type which reacts with themetal of the articles under treatment to form a protective coatingthereon includinga spraying chamber having a plurality of dischargenozzles therein, the combination of a tank for collecting excess sprayedsolution and accommodating the latter during settling of any solidmatter introduced into said solution during operation, said tank havingan inlet at one end portion and an outlet at its opposite end portion,and means in said tank for causing repeated reversed flow of saidcollected solution laterally of said tank in passing from said inlet tosaid outlet so as to provide time for settling out of said solid matter.

3. In rustproong apparatus having means for continuously spraying andre-spraying a rustproong solution of the type which reacts with themetal of the articles under treatment to form a protective coatingthereon including a spraying chamber having a plurality of dischargenozzles therein, the combination of a tank below said spray chamber forcollecting excess sprayed solution havingI an inlet at one end portionand an outlet at its other nd portion and having a sump at its inlet endportion for receiving the main portion of the settled solid matterintroduced into said solution by said reaction and during operationthereof, and means in said tank for causing repeated reversed flow ofsaid solution laterally of said tank in passing from said inlet to saidoutlet so as tovprovide time for settling out of substantially any solidmatter not deposited in said sump and to hold said'solution againstiiowing directly from the vicinity of said sump and carrying solidmatter deposited thereinto to said outlet.

4.*Rustproong apparatus comprising a rustprooing unit including a closedrustproofing solultion applying system having a plurality of spraynozzles, a collecting and settling tank for receiving f excess sprayedsolution and having means for delivering solution from Vsaid tank tosaid spray nozzles under pressure; a rinsing unit adjacent adjacent saidrustproong unit including a closed rinse liquid spray system having aplurality ofl spray nozzles, a tank for collecting rinse liquid andmeans for delivering the latter fromv said rinse liquid tank to saidrinse liquid spray nozzles under pressure; and means including one ofsaid delivering means for transferring said rustproong solution fromsaid rustprooi'lng unit to said rinse liquid tank preparatory forflushing said rustproong solution applying system.

5. Rustproong apparatus comprising a rustl proong unit including aclosed rustproong solution applying system having a plurality of spraynozzles, a collecting and settling tank for receiving excess sprayedsolution and having means for delivering solution from said tank to saidspray nozzles under pressure; a rinsing unit said rustproong unitincluding a closed rinse liquid spray system having a plurality of spraynozzles, a tank for collecting rinse liquid and means for delivering thelatter from said rinse liquid tank to said rinse liquid spray nozzlesunder pressure, means for transferring said rustproong solution fromsaid rustprcong unit to said rinse liquid tank preparatory for flushingsaid rustproong solution applying system, and means for returning saidrustproofing solution from said rinse liquid tank directly to the spraynozzles of said rust-proofing unit.

6. Rustproong apparatus including a rustdelivering solution thereto, aliquid rinsing system having a rinsing liquid supply tank and means fordelivering liquid thereto, and means including one of said deliveringmeans for transferring the solution of said rustprooiing spraying systemto thetank of said rinsing system to condition said rustproofingspraying system to be flushed.

'7. Rustprcoiing apparatus including a rustprooflng solution sprayingsystem having a supply tank and a plurality of discharge nozzles, aliquid rinsing system having a rinsing liquid supply tank, a pump insaid spraying system for delivering rustprooflng solution to saidnozzles under pressure, and a connecting conduit between said pump andsaid rinse liquid supply tank for transferring rustprooflng solutionthereto from said rustproofing solution tank by the action of said pumpto condition said rustprooiing spraying system to be iiushed.

8. Rustproong apparatus including a rustproofing solution sprayingsystem having a supply tank and a plurality of discharge nozzles, a

liquid rinsing system having a rinsing liquid supply tank and aplurality of discharge nozzles, a

liquid rinsing system having a rinsing liquid supply tank, a pump insaid spraying system for delivering rustproong solution to said nozzlesunder pressure, a connecting conduit between said pump and said rinseliquid supply tank for transferring rustprooi'lng solution thereto from"said pump to .condition said rustproong spraying system to be flushed,and means connecting said rinse liquid supply tank with said sprayingsystem for returning said solution directly to said nozzles under theaction of said pump after said ushing operation.

10.--Rustproong apparatus including a rustproofing solution sprayingsystem having a supply tank and a plurality of discharge nozzles, a-liquid rinsing system having a rinsing liquid supply tank, a pump insaid spraying system for delivering rustproong solution to said nozzlesunder pressure, a connecting conduit between said pump and said rinseliquid supply tank for transferring rustproong solution thereto fromsaid rustproong solution tank by the action of said pump to conditionsaid l rustproong spraying system to be flushed, means connecting saidrinse liquidsupply tank with said spraying system for returning saidsolution directly to said nozzles under the action of said pump aftersaid ilushing operation, and valve mechanism for selectivelypredeterminingthe course of flow of said solution.

11. Rustproong apparatus including a spraying chamber, dischargenozzlesl in said chamber for spraying a rustproong solution thereinto, atank below said chamber having a top closure extending over all but alimited extent of one end 2,089,648 rustproofng solution tank by theaction of said.

portion thereof and declined toward said end portion, a sump registeringwith the open portion of the top of said tank and extending below thebottom thereof for Areceiving solid matter introduced into said solutionduring operation thereof, a plurality of bailles in said tankv extendinglaterally thereof, opposite side edges of adjacent bailles being spacedfrom the opposite side Walls of said tank respectively to provide atortuous path for said solution, and means fordelivering solution fromthe end portion of said tank opposite to said sump to said nozzles.

l2. In rustproong apparatus having means for continuously spraying andre-spraying a rustproong solution of the type which reacts with themetal of the'articles under treatment to form a protective coatingthereon including a spraying chamber having a plurality of dischargenozzles therein, the combination. of a tank for collecting excesssprayed solution and accommodating the latter during settling of anysolid matter introduced into said solution during operation, said tankhaving an inlet and an outlet, and means including a plurality ofbaille'plates in said .tank

for causing the solution collected in said tank to follow a tortuouspath in passing through said tank between said inlet and outlet.

ROBERT H. GORDON.

